Limera1n is out to jailbreak iOS 4.1. Now, it’s best time to save SHSH blobs for iOS 4.1 so that you may always downgrade to iOS 4.1 and jailbreak your iPhone and iPod Touch. In this guide you’ll learn how to save SHSH blobs of iOS 4.1 for iPhone 4, 3GS, 3G, iPod Touch 4G, 3G, 2G with a single click using TinyUmbrella.

NOTE:

You can save SHSH blobs for iOS 4.1 only if it’s being signed by Apple. Go grab your SHSH blobs for iOS 4.1 before it’s too late. Apple stops signing a firmware when an updated version is out.

TinyUmbrella can save SHSH blobs regardless of jailbreak.

With TinyUmbrella you can save SHSH blobs for iOS 4.1 even if you’re on older iOS.

it is very easy , use PPwnage 4.1.2 tool and you can upgrade to 4.1 , preserve you baseband and unlock with ultrasn0w 1.1.1.; if you don’t have a MAC , u can use redsn0w 0.9.6.2 to put your iphone in DFU mode and a custom 4.1 firmware ( made with Pwnage ) to restore ; after it ultrasn0w !
Enjoy !